docstr: Subtract two Epoch's or a Duration from an Epoch.
  
  Valid:
  Duration = Epoch - Epoch
  Epoch = Epoch - Duration
  
  = INPUT VARIABLES
  - rhs     The Epoch to subtract.
  
  = RETURN VALUE
  - Returns either the duration between to Epoch's or the a new
    Epoch that is the result of subtracting a duration from an epoch.
docstr_tok: ["Subtract","two","Epoch","'s","or","a","Duration","from","an","Epoch",".","Valid",":","Duration","=","Epoch","-","Epoch","Epoch","=","Epoch","-","Duration","=","INPUT","VARIABLES","-","rhs","The","Epoch","to","subtract",".","=","RETURN","VALUE","-","Returns","either","the","duration","between","to","Epoch","'s","or","the","a","new","Epoch","that","is","the","result","of","subtracting","a","duration","from","an","epoch","."]
code: def __sub__(self, rhs):
      """
      Subtract two Epoch's or a Duration from an Epoch.
  
      Valid:
      Duration = Epoch - Epoch
      Epoch = Epoch - Duration
  
      = INPUT VARIABLES
      - rhs     The Epoch to subtract.
  
      = RETURN VALUE
      - Returns either the duration between to Epoch's or the a new
        Epoch that is the result of subtracting a duration from an epoch.
      """
      # Delay-load due to circular dependencies.
      import matplotlib.testing.jpl_units as U
  
      # Handle Epoch - Duration
      if isinstance(rhs, U.Duration):
          return self + -rhs
  
      t = self
      if self._frame != rhs._frame:
          t = self.convert(rhs._frame)
  
      days = t._jd - rhs._jd
      sec = t._seconds - rhs._seconds
  
      return U.Duration(rhs._frame, days * 86400 + sec)
  
file_path: matplotlib/lib/matplotlib/testing/jpl_units/Epoch.py
imports: import functools
  import operator
  import math
  import datetime
  from matplotlib import _api
  from matplotlib.dates import date2num
label_desc: Use image node_id 8 for calling the Epoch obj's underlying member method code with example usage: obj.__sub__(rhs) and returns: U, unknown